1. Field of the Invention
The present invention relates to a kit for contact lens sterilization, as well as to a method for contact lens sterilization. The present invention is applied to sterilization of known contact lenses composed mainly of, for example, methyl methacrylate, silicone-containing methacrylate, hydroxyethyl methacrylate, butyl acrylate or the like.
2. Description of the Related Art
Methods for sterilizing contact lenses to kill bacteria and Eumycetes adhering thereto are already known and various compositions have been proposed for this purpose.
For example, Japanese Patent Application Kokai (Laid-Open) No. 132115/1982 discloses a method for contact lens sterilization by the use of a chlorhexidine salt as a disinfectant. However, when this method is applied to the repeated treatment of a soft contact lens, even if the chlorhexidine salt is used in a low concentration, there occurs adsorption and accumulation of the salt by and on the lens because of the properties of the soft contact lens; hence, it is feared that the disinfectant accumulated and concentrated on the lens during the use of the lens is released from the lens and causes damage to the cornea. Japanese Patent Application Kokai (Laid-Open) No. 105457/1984 discloses a method for contact lens sterilization wherein a contact lens is sterilized with hydrogen peroxide and, after the completion of the sterilization, the lens is immersed in a sodium pyruvate solution to neutralize the remaining hydrogen peroxide. These methods, however, are defective in that the treatment for making nontoxic the disinfectant remaining on the contact lens may be forgotten and the visual check of the completion timing of such a treatment is difficult.
Thus, the conventional methods for contact lens sterilization have a sufficient sterilization effect but have drawbacks, for example, in that the safety of sterilized lens is low, that the sterilization operation becomes lengthy because two disinfecting components are added separately, that the addition of one disinfecting component is forgotten resulting in the reduced safety of sterilized lens, and that the safety of sterilized lens cannot be ascertained.